<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
		<meta http-equiv="X-UA-Compatible" content="IE=edge">
		<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
  
  <div id="app"></div>

  <script src="https://unpkg.com/@vue/reactivity@3.0.5/dist/reactivity.global.js"></script>
  <script>
    const {effect,ref}=VueReactivity;
    function renderer(domString,container){
      container.innerHTML=domString;
    }
    const count=ref(1);
    effect(()=>{
      renderer(`<h1>${count.value}</h1>`,document.getElementById("app"))
    });
    count.value++;
  </script>
</body>
</html>